• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.11a
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• pp.94-95
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• 2011

선박 엔진 크랭크 케이스 내부의 기계 결함으로 발생하는 윤활 오일 미스트 발생은 폭발뿐만 아니라 급격한 온도와 압력상승으로 2차 폭발을 야기하는 등 큰 피해를 가져와 현재 선박용 엔진의 크랭크 케이스에 오일미스트 검출장치의 설치를 의무화 하고 있는 추세이다. 본 논문에서는 이러한 피해를 줄이기 위하여 광 산란 방식을 이용한 오일 미스트 검출장치를 구현하였으며, 구현된 오일미스트 검출 장치의 오일미스검출 센서 센싱 성능은 전기적, 광학적 그 외 환경적 요인으로 인하여 출력값이 일정하지 못해 각각의 오일미스트 검출 센서를 보정해야 한다. 본 논문에서는 크랭크케이스마다 장착되는 오일미스트 검출 센서의 오차를 최소화하기 위하여 정밀하게 Calibration된 Reference Data를 기반으로 최소자승법을 적용하여 센서를 Calibration하였으며, 그 결과 각각의 오일미스 검출센서의 오차를 기존 방법과 비교하여 최소화할 수 있었다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.6
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• pp.87-94
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• 2003

This paper presents results of the development of the turbo generator system with structure which is HSG(High Speed Generator) installed directly to gas-turbine engine. Turbo generator with a high speed motor-generator directly has many advantages aspects of weight, size, lubrication system and complexity of the system compared of conventional turbo generator system with a gear box. But because of direct high speed operation of the high speed generator, we have to need stable high speed motor driving algorithm for perfect engine ignition when engine start. Also we have to need the design of the Power conditioning unit(PCU) for converting high speed AC output power to conventional AC power or needed DC power.

• Journal of the Korean Institute of Gas
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• v.20 no.2
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• pp.10-15
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• 2016

This paper is to analyze and study the failure examples of refrigerant gas in automotive air conditioner. The first example, the air conditioner compressor continually operated that the refrigerant was leaked in air conditioner system. By lubrication shortage, the piston was partially sticked on cylinder of air conditioner compressor inner part. This was caused the phenomenon of engine operation trouble by load increasing with engine rpm variation during engine running. The second example, it sought the fact that the air conditioner refrigerant gas was leaked from air conditioner compressor to condenser high pressure pipe toward rear air conditioner checking with the lines of air conditioner. The third example, the refrigerant gas of air conditioner found that was leaked imperceptible from condenser inner by crack that was generated on the fins of air conditioner condenser. Therefore, the air conditioner system that maintain the air conditioner by decreasing the in-car temperature must meticulously manage to not leak the air conditioner refrigerant gas.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.1
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• pp.28-31
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• 2015

Electromotive forces (EMF) are generated by electrical equipment and engine shafting with a number of reasons. The shaft and bearing which is insulated by lubricating oil acts as a condenser, being able to store this EMFs. The electromotive force on the hull and shaft, with very few exceptions, has anode voltage on it. Electrical spark of the anode voltage on the shaft may lead to corrosion. Hence, in order to prevent ship's shaft and propeller corrosion, shaft grounding system are installed and operated. The shaft EMF voltage measurement methods was measured using 24bit 2 channels A/D converter of NI company and Labview software. 1 channel was propeller shaft's voltage and the other was M/E engine rpm gauge. In this paper, the generated electromotive force was analyzed and modeled with result of the analysis. As a result, the main shaft's electromotive force was in direct proportion to the main engine's revolution. However, over the specific R.P.M., it was reduced gradually. In addition, higher electromotive force on the shaft was identified during engine's ahead direction than the astern direction. The generated electromotive force is only minor compared to the shaft grounding system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.74-79
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• 2019

The military vehicle produces electric power through an engine-integrated serial hybrid generator that is connected to the engine and does not have a separate generator installation space. However, depending on the mechanical characteristics of the connection between the generator and the engine, iron oxide for internal rusting and lubrication grew scattered. The iron oxide is adhered to the starter to deteriorate the starting performance, and there is a problem that the noise of the leg due to wear of the gear is increased. To solve this problem, the connection spline material and the surface treatment of the engine were improved and the shape was changed to a grease sealing type to prevent the generation of iron oxide inside. As the shape of the generator connector composing the shafting system was changed, the integrity of the structure was confirmed through the torsional endurance test. In addition, through the actual vehicle load test, it was verified that no corrosion occurred during the target life span without internal corrosion. It was confirmed that the anti-scattering structure of the grease effectively suppresses the generation of iron oxide, thereby reducing the noise generated from the generator. In this paper, we propose a fundamental solution to the degradation of the starter and the noise generation by preventing the back corrosion caused by the serial hybrid generator installed between the engine and the transmission.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.5
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• pp.66-74
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• 1998

The operating torque and tribological characteristics of a cam/tappet system of an I.C. engine have an important effect on the engine efficiency. More power is lost for higher operation torque which is affected by the friction of a cam/tappet system. In this work experimental investigation of the torque behavior of a cam/tappet system was conducted to get tribological characteristics. Specifically, the torque was measured with respect to oil temperature and camshaft speed. The torque decreased with increasing camshaft speed because of decreasing friction coefficient but was hardly affected by the oil temperature. Also, the torque was the largest near the cam nose region.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1993.04a
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• pp.54-58
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• 1993

Cu, Si, Mg, Ca, Cd, Sn, Pb등이 첨가되는 Al계 bearing 합금은 베어링 특성이 우수하여 최근 자동차드의 엔진 부품용 베어링소재로 많이 사용되어지고 있다. 합금원소 Si는 합금의 경도를 향상시키며 Si-rich한 경한 입자를 생성시켜 소착저항력(antiseizure)을 향상시키며 또한 합금의 주조성도 향상시켜 내마모성이 요구되는 Al계 베어링 합금에 주합금원소로 첨가된다. 본 연구에서는 강제죠반법과 급냉응고법을 이용하여 Al-Pb-Gu계와 Al-Si-Gu-Pb계 베어링합금을 제조하였다. 베어링합금이 급냉응고법으로 제조되었기 때문에 합금의 기지에는 Cu가 과포된 상태로 존재하여 석출경화에 앞서 행하여지는 용체화처리와 같은 효과가 얻어졌다. 본 실험에서는 Cu가 과포화된 기지를 갖는 주조상태의 시료를 시효열처리하여 석출경화된 베어링합금을 얻어서 석출경화에 의한 기지강화가 베어링합금의 내마모성질에 어떠한 효과를 가져오는지 규명하였다.

• Tribology and Lubricants
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• v.24 no.3
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• pp.133-139
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• 2008

In recently designed diesel engines, the running conditions for piston pin bearings have become very severe due to combustion pressure and temperature increase. In this paper, it will be investigated the tendency of piston pin rotating motion by calculating the friction coefficient at piston pin bearings, the oil film thickness and the frictional torques induced by hydrodynamic shear stress. Finally, the pressure distributions on the oil film of piston pin bearings will be found by two-dimensional lubrication analysis in order to help the optimum design of the bearings of piston pin. Specially, it is investigated the effects on the film pressure distribution due to the change in maximum combustion pressure.

• Tribology and Lubricants
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• v.14 no.3
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• pp.87-93
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• 1998

Crank pin bearing in two-stroke marine diesel engine is operated under quite severe conditions since the elements are big and heavy and the sliding speed is very slow. Therefore it is very difficult to form oil film. In this paper, two types of bearings with different groove shape are compared. One has circumferential oil groove at lower position and the other has lengthwise oil groove at upper position. Bearing clearance, oil inlet pressure and length to diameter ratio are selected as design parameters. Locus of journal center and minimum oil film thickness are investigated to compare two cases.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2004.11a
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• pp.233-236
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• 2004

An experimental study was conducted to evaluate characteristic variation of diluted engine oil by diesel fuel and its effects on engine components. Especially, engine oil was made to have $15\%$ fuel content. To predict existing diesel fuel content in engine oil after test was used the viscosity calibration curve. About $54\%$ percent of diesel fuel in diluted engine oil was distillated by various paths related to reciprocating motion of piston and the rest diesel fuel plays an important role for decreasing engine oil viscosity. Test results show that lowered engine ell viscosity by diesel fuel dilution become a reason of increasing engine elements wear, Therefore, this caused the quantity of blow-by gas to increase and main gallery pressure to decrease.